1. Field of the Invention
This invention relates to anti-microbial dental restorative compositions and a method of manufacture thereof. In particular, this invention relates to anti-microbial dental restorative compositions comprising salicylic acid, 4-amino salicylic acid, esters of salicylic acid, esters of 4-aminosalicylic acid, or sulfanilamide.
2. Brief Discussion of the Related Art
Dental restorative compositions include dental primers, adhesives, liners, filling materials, sealants, and luting cements, among others. Dental restorative compositions generally comprise at least one polymerizable monomer or prepolymer and a polymerization initiation system. Preferred polymerizable monomers or prepolymers are ethylenically unsaturated, and even more preferably acrylic and methacrylic resinous materials, with or without an acid moiety. Such compositions are disclosed, for example, in U.S. Pat. Nos. 3,066,142, 3,179,784, 3,751,399, 3,926,906, 4,544,359, 4,659,751, 5,218,070, 5,276,068, 5,348,475, and 5,348,988, which are incorporated by reference herein.
Dental restorative compositions are used to restore function and anatomy of a tooth both in human and animals either temporarily or permanently. During restoration of the tooth, bacterial species can enter the tooth, causing secondary decay. Additionally, if the residue of primary decay is not completely removed during restorative treatment, secondary decay of the tooth may continue underneath the site of restoration.
Incorporation of anti-microbial agents into certain dental compositions is known. For example, U.S. Pat. No.3,925,895 to Kliment et al., discloses a hydrophilic polymerizable acrylate or methacrylate root canal filling material. Kliment discloses that various medicaments can be incorporated into the polymerizable monomer, such as Novocaine (procaine hydrochloride), Benzocaine (ethyl aminobenzoate), ascorbic acid, butacaine sulfate, dibucaine hydrochloride, Bacitracin, hexachlorophene, lincomycin hydrochloride, p-amino salicylic acid, sulfadiazine, procaine penicillin, aureomycin, streptomycin, tetramycin, chloramphenicol, penicillin, neomycin sulfate, succinoyl-sulfathiazole, cetyl pyridinium chloride, trimethyl benzyl ammonium chloride, triethyl dodecyl ammonium bromide, sulfathiazole, sulfanilamide, phenobarbital, pentabarbital sodium, butabarbital, diethyl stilbestrol, tetracycline, and xylocaine. While useful as root canal sealing materials, such swellable hydrophilic compositions are not themselves useful as dental primers, adhesives, liners, sealants, or cavity filling materials.
U.S. Pat. No 5,385,728 to Suh discloses a dental etching gel containing the quaternary ammonium compound benzalkonium chloride. One drawback of quaternary ammonium compounds is that their effectiveness is decreased in the presence of calcium or magnesium ions, or such as dental gauze. Another more serious drawback is that rather they can support the growth of some bacterial species belonging to the genus Pseudomonas.
Fluoride is used in dental restorative compositions as an antimicrobial agent to kill the bacteria and prevent secondary decay. Fluoride exhibits bactericidal activity when released from silicate cement continuously. However, the release of fluoride from the dental restorative resin composite material ceases after a short period of time. Fherefore, the longterm therapeutic effectiveness of fluoride-containing dental resin composite is questionable. Dental etchants and tooth surface conditioners, such as oral rinses, containing anti-microbial agents have also been disclosed. U.S. Pat. No. 4,939,132 to Colburn et al. discloses 5-alkylsulfonylsalicylanilides and their use as antiseptic compositions having anti-microbial activity against organisms such as Streplococcus mutans. However, these materials also provide only a temporary anti-microbial effect as they are rinsed off or otherwise removed from the tooth.
One approach to resolving this problem is disclosed in U.S. Pat. No. 5,408,022 and 5,733,949 to Imazato et al., which disclose anti-microbial polymerizable compositions comprising an ethylenically unsaturated monomer, at least one mono-, di-, or tri-functional ethylenically unsaturated monomer having anti-microbial activity, and a polymerization initiator. While suitable for their intended purposes, these compositions are restricted to use of copolymerizable anti-bacterial agents which are expensive and/or of limited availability.
Accordingly, there remains a need in the art for anti-microbial dental compositions suitable for use as dental primers and adhesives, liners, sealants, luting cements, and restorative materials that will sustain anti-microbial activity after curing. There further remains a need for such anti-microbial dental compositions that will sustain anti-microbial activity over a period of time while not causing harm to the living dentin and surrounding tissues. There further remains a need for anti-microbial dental compositions, wherein the anti-microbial agent provided in the composition will not adversely affect the functioning of the composition's restorative properties.